CVE-2024-26799

What it actually does

Uninitialized pointer dmactl in __lpass_get_dmactl_handle retains a garbage value on invalid dai_id, causing the subsequent null check to evaluate unpredictably and potentially allowing use of an invalid pointer in ASoC Qualcomm audio DMA handling.

Why it matters to the business

May cause kernel instability, crashes, or undefined behavior during audio operations on affected Linux systems, increasing operational risk for devices relying on Qualcomm sound hardware until patched.

How an attack unfolds

An attacker with local access triggers the qcom audio driver path that calls __lpass_get_dmactl_handle with an invalid dai_id, allowing the uninitialized dmactl pointer containing garbage to bypass the null check and lead to memory corruption or crashes.

How to fix it

Update the Linux kernel to a version containing commit 99adc8b4d2f38bf0d06483ec845bc48f60c3f8cf or later; rebuild and deploy the fixed kernel image.

How to confirm the fix worked

Verify the presence of the initialization dmactl = NULL in __lpass_get_dmactl_handle in sound/soc/qcom/lpass-cdc-dma.c and confirm the clang warning is resolved after applying the fix.

Typical attack path

1. Obtain local code execution or user privileges on the target Linux system
2. Load or interact with the ASoC qcom sound driver to invoke __lpass_get_dmactl_handle
3. Supply an invalid dai_id value to bypass pointer initialization
4. Trigger the branch condition that evaluates the garbage dmactl value
5. Exploit resulting memory corruption for denial of service or further escalation

How to detect it

Review kernel logs for oops or warnings originating from lpass-cdc-dma.c around audio DMA initialization; inspect for unexpected branch behavior or pointer faults in sound driver paths.

What your security team should do

• Prioritize kernel updates on systems using Qualcomm audio drivers
• Monitor for kernel oops or panics related to lpass-cdc-dma after exposure windows
• Apply the fix in all downstream distributions and embedded builds